Seed and fruit production are multi-billion dollar commercial industries and primary sources of income for numerous states in the United States and for many countries around the world. Commercially valuable seeds include, for example, canola, cottonseeds and sunflower seeds, which are prized for the vegetable oil that can be pressed from the seed. The seeds of leguminous plants such as peas, beans, and lentils also are commercially valuable as they are rich in proteins, with soybeans, for example, consisting of 40-45% protein and 18% fats and oils. In addition, coffee is a valuable crop made from the dried and roasted seeds of Coffea arabica plants, while chocolate is made from the cacao seed or “bean.” Similarly, many fruits and seeds are commercially valuable, including, for example, corn, rice, wheat, barley and other cereals, nuts, legumes, tomatoes, and citrus fruits. For example, corn seeds are made into many food items or items used in cooking, such as taco shells, corn oil, tortillas, corn flakes, corn meal, and many others. Corn is also used as raw material in many production processes, including but not limited to, feed and ethanol production.
Seed and fruit production are both limited inherently due to biotic and abiotic stress. Soybean (Glycine max), for instance, is a crop species that suffers from loss of seed germination during storage and fails to germinate when soil temperatures are cool (Zhang et al., Plant Soil 188: (1997)). This is also true in corn and other plants of agronomic importance. Improvement of abiotic stress tolerance in plants would be an agronomic advantage to growers allowing increasing growth and/or germination in cold, drought, flood, heat, UV stress, ozone increases, acid rain, pollution, salt stress, heavy metals, mineralized soils, and other abiotic stresses. Biotic stress, such as fungal and viral infection, also cause large crop losses world wide.
Traditional breeding (crossing specific alleles of one genotype into another) has been used for centuries to increase biotic stress tolerance, abiotic stress tolerance, and yield. Traditional breeding is limited inherently to the limited number of alleles present in the parental plants. This in turn limits the amount of genetic variability that can be added in this manner. Molecular biology has allowed the inventors of the instant invention to look far and wide for genes that will improve stress tolerance in plants. Our inventors sought to determine how other organisms react to and tolerate stressful conditions. The cold shock proteins are part of a system used by bacteria and other organisms to survive cold and stressful conditions. It was posited by the inventors that placing genes encoding the cold shock proteins, and proteins related to them, into plants and expressing them would increase the cold, drought, heat, water, and other abiotic stress tolerance of plants as well as fungal, viral, and other biotic stress tolerance of plants. They also believe that using genes that are homologous to cold shock proteins, or have sequence similarity, would also increase biotic and abiotic stress tolerance.
This invention is useful to farmers to limit their losses due to biotic and abiotic stress.